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(No Mode l.) I J. AMMON.

Piano Forte Action.

No.. 237,797. Patented Feb. 15,1881.

' UNiTEn STATES PATENT @FFICE:

JOHN AMMON, OF NEIV YORK, N. Y., ASSIGNOR TO \VESSELL, NICKEL 8s GROSS, OF SAME PLACE.

PIANO-FORTE ACTION.

SPECIFICATION forming part of Letters Patent No. 237,797, dated February 15, 1881.

Application filed May 31, 1880. (No model.)

To all whom it may concern:

Be it known that I, JOHN AMMON, of the city of New York, in the county and State of New York, have invented a certain new and useful Improvementin Piano-Forte Actions, of which the following is a specification.

In a piano-forte action as ordinarily constructed the jack, after acting upon the hammer-butt to raise the hammer, is thrown out from the notch in said hammer-butt, and the distance to which it is so thrown out is controlled by what is termed the blocking of the lower arm of the jack against a cushion on the jack-bottom,by which the jack is attach ed to the key. The means heretofore commonly used for regulating this blocking is to pare away the bottom of the jack, or to build up or add to the cushion, according as it is desired to let the jack fall farther, or not so far, out of the notch.

The object of this improvement is to provide more conveniently for adjusting or regulating the blocking; and to this end theinvention consists in the combina'tiomwith thejack andjackbottom, by which it is secured to the key, of a regulating-screw placed between the lower arm of the jack and the jaok-bottom,\vhereby the said adjustment or regulation may be convenien tly effected. I preferably also combine with the above a let-off screw, which may be fixed in some stationary partas, for instance, in the hammer-rest rail.

In the accompanying drawings, Figure 1 represents a side view of the playing end of a key and the hammer-action, the hammer having been thrown up and the jack released from the butt to permit the hammer to fall; and Fig. 2 represents a similar view, in which all the parts are at rest before the key is struck.

Similar letters of reference designate corresponding parts in both figures.

A designates the playing end of a piano-forte key; B, the jack-bottom secured thereto, and having hinged to it the jack 0. D designates the hammer-rail, to which the hammer-flanges E are secured. F designates the ham mer-butt, containing the usual notch, a, for thejack. G designates the shank, and G the head, of the hammer. H designates the hammer-cushion.

I designates the hammer-rest rail, and J the let-off screw, with which the lower arm, Z), of thejack comes in contact as the key is raised, and by which the jack is thrown back out of the notch a in the llftllllnldflltt F. All these parts are of ordinary construction, and there fore need no special explanation.

In ordinary actions of the kind above described the only means of blocking the jack upon thejack-bottom, or-ot' regulating or determining the backward movement, is bybuilding up upon thejack-bottom B with cloth, under the lower arm, I), of the jack, to throw the jack forward, or paring away the under side of said lower arm when it is desired to move the jack backward. In order to provide a means whereby this blocking adjustment or regulation may be conveniently effected, I employ a regulating-screw, placed between the jack-bottom and the lower arm of the jack, which may be regulated to block thejack atthe required distance from the hammer-butt. This screw might be screwed into the jackbottom and the cushion placed on the lower arm of thejack; but as here shown the screw 0 is inserted in the lower arm, I), of the jack and cushions upon thejack-bottom. The screw 0, by being turned in or out, as the case may require, will cause the blocking of thejack to be effected with its upper end at a nearer or less distance from'the notch in the hammerbutt.

I am aware that it is old to employ a let-off screw inserted through the lower arm of the jack, and between it and thejack-bottom, so

that as soon as thejack-bottom strikes against the screw the jack will be thrown out of the notch in the hammer-butt; but my blockingscrew is different from this in that it prevents thejack from being thrown out beyond a certain point.

What I claim as my invention, and desire to secure by Letters Patent, is

l. The combinatiomwith ajack-bottom and a jack for a piano-forte action, of a regulatingscrew between the jack-bottom and the lower arm of the jack, all constructed and arranged as described,whereby the said regulating-screw serves as a means of regulating the distance to which the jack is thrown out of the ham- 1 and serving as a means of regulating the dis mer-notch, substantially as specified. tance to which the jack is thrown out of the 2. The c0mbinati0n,with a jack-bottom and hammer-notch, substantially as specified. jack for a piano-forte action, of a let-off screw 5 for moving thejack out of the hammer-notch, Vitnesses:

and an independent regulating-screw between FREDK. HAYNES, the jack-bottom and the lower arm of the jack, THOMAS E. BIRCH.

JOHN AMMON. 

